(1) Field of the Invention
This invention relates to improvements in a readily splittable plastic cannula used for inserting a long catheter into a body cavity such as a blood vessel.
(2) Description of the Prior Art
The usual plastic cannula has a role of securing a guide section for smoothly inserting a long catheter or the like into the body cavity. After the catheter has been inserted, however, it constitutes an abstract in a subsequent operation. For this reason, a plastic cannula which can be removed by splitting after the insertion of the catheter or the like has been developed.
Such readily splittable plastic cannula are disclosed in Japanese Utility Model Registration 51-1661, Japanese Patent Laid-Open 56-11069 and Japanese Patent Laid-Open 59-91968. These disclosed structures are capable of being split or divided in the longitudinal direction so that they can be removed from the body cavity by pulling them after their role of guiding a catheter is over.